MRI OF SHOULDER INJURY
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Transcript of MRI OF SHOULDER INJURY
MRI OF SHOULDER JOINT
Dr Krishna Kiran MD.DNB.FRCR RadiologistCalicut
This presentation is intended for medical and allied professionals.
What is T1,T2.. And many other fancy names used in MRI..??
T2 T1 FAT SUPPRESSEDSTIR/PDFS
Common sequences in MRI shoulder
How do you do shoulder MRI..
Shoulder MRI is done in a plane parallel to supraspinatus. Generally sequences obtained are Coronal plane T1, T2, Fatsuppressed (STIR or PDFS) Axial - T1, fatsuppressed Sagittal - T2 and fat suppressed.
Key section in shoulder coronal image in the middle third
Anterior coronal section
Posterior coronal section shoulder
Sagittal section
Axial anatomy
After review of anatomy , Let us proceed to our case.
CASE 1?ROTATOR CUFF TEAR
Full thickness tear supraspinatus tendon except fibers in anterior third
Complete tears of supraspinatus tendon are accompanied by muscle atrophy and fatty infiltration.
These are important negative prognostic factors for tendon repair and shoulder arthroplasty.
Muscle thickness using Fat occupancy ratio and fatty infiltration of muscle can be assessed on MRI.
Fat occupancy ratio
Reduced fat occupancy Normal fat occupancy
Fatty infiltration supraspinatus
Normal supraspinatus
Case 2
? Rotator cuff tear
Avulsion Fracture greater tuberosity of humerus
Case 3
?RCT
Rimrent or PASTA tear
Rimrent or PASTA tear
A partial tear that extends to articular surface does not extent to bursal surface.
Case 4
Recurrent Dislocation shoulder
Anterior middle posteriorCoronal sections
Posterior sections of shoulder
Hill Sach Lesion
Anterior labral tear
Normal anterior labrum for comparison
Labral clockClockwise approach to labrum is the easiest way to diagnose labral tears and differentiate them from normal variants.
ABER viewAbduction external rotation view of shoulder is utilized to detect subtle soft tissue pathology of anteroinferior labrum and rotator cuff.
Types of anteroinferior labral tears.
Bankart lesion
Perthe lesion
ALPSA lesion
Case 5
Shoulder pain and limitation of movement.
Anterior middle
posterior
Anterior capsule thickening indicative of adhesive capsulitis.
Normal for comparison
Case 6
Shoulder pain on overhead hand movement
Anterior middle
posterior
Anterior middle
posterior
Supraspinatus tendonitis / tendinopathy
MRI shows tendon enlargement and mild intratendinous hyperintense signal.
Case 7
Suspected scapula fracture
3D CT is done to assess scapula and adjacent injuries.
Case 8
An athlete complains of pain on throwing and overhead movement of arm.
MR Arthrogram
Hyperintense signal within labrum extending posteriorly. Indicative of SLAP lesion. (Superior Labral anteroposterior tear)
Labrum shows several anatomical variations. Conventional MRI is not
accurate in diagnosing labral tears (40-70% sensitivity and specificity) MR
Arthrography is more accurate (90-95% sensitivity and specificity)
CASE 1OHistory of Trauma
AP shoulder
Y view or scapula lateral
Posterior dislocation
Internally rotated humerus giving light bulb appearance. Y view showing
posterior dislocation.
Other views of shoulderOutlet or Neer`s view
Other viewsAxillary view
What about ultrasound..?
Useful tool in
• Rotator cuff tendinopathy or
tear.
• Calcific tendonitis.
• Subacromial bursal effusion.
Limitations
• Many parts of joint can not be
assessed.
• Operator dependent
Coronal STIR Coronal T2
Some sequences reveal mild bright signal / hyperintensity within
substance of supraspinatus. If seen without tendon enlargement is
indicative of artifact called magic angle phenomenon. Is said to be due
to orientation of collagen fibers.
What is magic angle phenomenon..?
What is difference between low strength and 1.5T magnet..?
0.2T
1.5 T
How accurate are shoulder MRI reports..? 15-20% of asymptomatic adults on shoulder
MRI revealed rotator cuff tears. A shoulder surgeon with correlation between
arthroscopy and MRI may be able to correlate image findings better.
In doubtful cases it is better to mutually discuss and proceed.
Sher et al JBJS 1995
What are types of acromion..?
Type 2 and 3 are associated with shoulder impingement
QUIZ
Shoulder , arm pain after suddenly lifting heavy weight
SLAP tear extending to biceps anchor
Take home points..
Shoulder is a complex joint , imaging also tends to be complex and prone for errors.
When in doubt discuss and proceed. Signal within tendon may not be
significant , remember magic angle ..!!